In the past, the semiconductor industry used various different device structures and methods to form semiconductor devices such as, for example, diodes, Schottky diodes, Field Effect Transistors (FETs), High Electron Mobility Transistors (HEMTs), etc. Devices such as diodes, Schottky diodes, and FETs have been manufactured from compound semiconductor substrates such as, for example III-N materials. Drawbacks with semiconductor devices made from III-N materials such as gallium nitride (GaN)/aluminum gallium nitride (AlGaN) materials include high reverse leakage currents and low reverse breakdown voltages. To overcome these drawbacks, semiconductor manufacturers have used a dielectric layer at the anode of the device to reduce the reverse leakage current. U.S. Patent Application Publication Number 2011/0133251 A1 by Zhi He published on Jun. 9, 2011, describes using a dielectric layer at the anode to reduce the reverse leakage current. Although He teaches a technique to mitigate a high reverse leakage current, the issue of a low reverse breakdown voltage remains.
Accordingly, it would be advantageous to have a structure and method for manufacturing a semiconductor component using a III-N semiconductor substrate that addresses the performance specifications and manufacturability. It would be of further advantage for the structure and method to be cost efficient to implement.
For simplicity and clarity of illustration, elements in the figures are not necessarily to scale, and the same reference characters in different figures denote the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description. As used herein current carrying electrode means an element of a device that carries current through the device such as a source or a drain of an MOS transistor or an emitter or a collector of a bipolar transistor or a cathode or anode of a diode, and a control electrode means an element of the device that controls current flow through the device such as a gate of an MOS transistor or a base of a bipolar transistor. Although the devices are explained herein as certain n-channel or p-channel devices, or certain n-type or p-type doped regions, a person of ordinary skill in the art will appreciate that complementary devices are also possible in accordance with embodiments of the present invention. It will be appreciated by those skilled in the art that the words during, while, and when as used herein are not exact terms that mean an action takes place instantly upon an initiating action but that there may be some small but reasonable delay, such as a propagation delay, between the reaction that is initiated by the initial action. The use of the words approximately, about, or substantially means that a value of an element has a parameter that is expected to be very close to a stated value or position. However, as is well known in the art there are always minor variances that prevent the values or positions from being exactly as stated. It is well established in the art that variances of up to about ten percent (10%) (and up to twenty percent (20%) for semiconductor doping concentrations) are regarded as reasonable variances from the ideal goal of exactly as described.